Merge pull request #11707 from smowton/smowton/fix/java-empty-multiline-comment

Java: handle printing an empty comment (/**/); add relevant tests

java/ql/test/library-tests/comments/PrintAst.expected

@@ -14,6 +14,18 @@ Test.java:
 #   21|     3: [Method] test
 #   21|       3: [TypeAccess] void
 #   21|       5: [BlockStmt] { ... }
+#   23|     4: [Method] method1
+#   23|       3: [TypeAccess] void
+#   23|       5: [BlockStmt] { ... }
+#   24|     5: [Method] method2
+#   24|       3: [TypeAccess] void
+#   24|       5: [BlockStmt] { ... }
+#   28|     6: [Method] method3
+#-----|       0: (Javadoc)
+#   25|         1: [Javadoc] /** JavaDoc for method3 */
+#   26|           0: [JavadocText] JavaDoc for method3
+#   28|       3: [TypeAccess] void
+#   28|       5: [BlockStmt] { ... }
 TestWindows.java:
 #    0| [CompilationUnit] TestWindows
 #    5|   1: [Class] TestWindows

java/ql/test/library-tests/comments/Test.java

@@ -19,4 +19,11 @@ class Test {
 	// an end-of-line comment with trailing whitespace        
 	//an end-of-line comment without a leading space
 	void test() {} // an end-of-line comment with preceding code
+
+        void method1() { /**/ } // A block comment containing the /** JavaDoc prefix }
+        void method2() { }
+        /**
+         * JavaDoc for method3
+         */
+        void method3() { }
 }

java/ql/test/library-tests/comments/toString.expected

@@ -8,6 +8,9 @@
 | Test.java:19:2:19:59 | // an end-of-line comment with trailing whitespace         |
 | Test.java:20:2:20:49 | //an end-of-line comment without a leading space |
 | Test.java:21:17:21:61 | // an end-of-line comment with preceding code |
+| Test.java:23:26:23:29 | /*  */ |
+| Test.java:23:33:23:86 | // A block comment containing the /** JavaDoc prefix } |
+| Test.java:25:9:27:11 | /** JavaDoc for method3 */ |
 | TestWindows.java:1:1:4:3 | /** A JavaDoc comment ... */ |
 | TestWindows.java:6:2:6:45 | /** A JavaDoc comment with a single line. */ |
 | TestWindows.java:8:3:8:27 | // a single-line comment |